Towards EPICS; high contrast spectroscopy

1. Towards EPICS; high contrast spectroscopy Fraser Clarke N Thatte, G Salter, M Tecza C Verinaud, M Kasper (EPICS co-PIs) R Gratton (EPICS science team) Fraser Clarke

2. EPICS top level requirements • EPICS is the proposed planet finding instrument for the E-ELT • Two modes of operation • Imaging spectroscopy • Polarimetric imaging • Top Level Requirements • 600-1700nm (goal 350-2500nm) [600-900 for Polarimetry] • R>50 for discovery; R>>50 for characterisation [Spectroscopy] • Nyquist sampled imaging (2mas/pixel) • 2” FoV (goal 4”) • Inner Working Angle < 30mas (goal 15mas) • Strehl at H~90% (I=9) [>50% at 600nm for Polarimetry] • Coronagraphic rejection better than 104 (tbc) • Polarimetric sensitivity 10-5 • Phase A study underway now. Due to be completed by Oct 2009. Fraser Clarke

3. EPICS key science • Young self-luminous gas giants in star forming regions or young associations • Determine frequency and mass distribution of giant planets • Detection and characterisation of mature gas giants at orbital distances between ~5 and 15AU in the solar neighbourhood (15pc) • Imaging and characterisation of warm or young Jupiters previously found by R.V. or imaging searches with smaller telescopes • Understand giant planets’ atmospheric composition and structure • Detection and 1st order characterisation of warm Neptunes, massive rocky planets and super-Earths around very nearby stars (<10pc); with ultimate goal of detecting such planets located in the HZ (M-dwarfs and systems <4pc) Fraser Clarke

4. EPICS consortium G Tinetti (UCL) Fraser Clarke

5. Oxford involvement in EPICS • Niranjan Thatte leads IFS workpackage • Oxford concentrates on Image Slicers • INAF/Padova (R Gratton) developing “BIGRE” lenslet approach • Oxford deliverables; • IFS optical design analysis • Slicer prototype • SINFONI coronagraph (not funded in EPICS Phase A, but present in list of deliverables!) • Data reduction algorithms Fraser Clarke

6. Speckles; limits on high contrast • Light not put into diffraction limited core of PSF interferes coherently to produce speckles • Some speckles, caused by imperfections in optical train, are long lasting (many minutes, or more), and cannot be integrated out • Super-speckles • Super-speckles are diffraction limited, and look like real objects at a given wavelength • => Major limit to contrast in current systems Fraser Clarke

7. A third way… (wavelength) Speckles scale with wavelength (/D), so they move out from central star as one goes to longer wavelengths Planets are at a fixed position on the sky which doesn’t change with wavelength Use wavelength scaling of Airy pattern and speckles to remove starlight and isolate planet’s signature. (Sparks & Ford 2002) Fraser Clarke

8. Concept demonstrator • AB Dor C as target • 5 mag fainter companion 200 mas away • VLT + SINFONI data • DDT P76 (end of January 2006) • 2 x 20 min on-source in two rotator settings • First Airy Null at 60 mas in K band. • Results published in; • Thatte et al 2007, MNRAS, 378, 1229 • Close et al 2007, ApJ, 665, 736 Fraser Clarke

9. Spectroscopy at the diffraction limit Input data cube (normalised) Fraser Clarke

10. Spectroscopy at the diffraction limit • Subtracted azimuthally averaged PSF • Stepping through in wavelength from 1.45-2.4um Fraser Clarke

11. Super speckles in the raw data • Subtract azimuthally averaged PSF • Monochromatic image • Super-speckles clearly visible Fraser Clarke

12. Super speckles after processing • Same wavelength slice after SD technique • Speckles well removed Fraser Clarke

13. 9 mag at 0.2” w/o coronagraph!! Thatte et al, 2007, MNRAS, 378, 1229 Fraser Clarke

14. Spectra of AB Dor C Fraser Clarke

15. Spectral type of AB Dor C Close et al., 2007,ApJ, 665, 736 Fraser Clarke

16. Steps towards EPICS • Continuing to improve SD technique for EPICS data (Graeme Salter) • Simulated data cube provided by C Verinaud for EPICS • 1024x1024 with 444 wavelengths • Many speckles and “N” planets… Fraser Clarke

17. Found 6 of 7 planets! • SD technique found 6 of 7 planets in the datacube (Differential imaging only found 2) • Particularly good further from star, where speckles move more. • Tiger-stripe issue understood (fitting error), and should be fixed now Fraser Clarke

18. Summary • EPICS phase A study progressing, and due for submission to ESO by Oct 2009 • Oxford leading IFS work package • Many pronged approach to investigating high contrast capabilities of image slicers • Slicer bench test in the lab • SINFONI coronagraph test on sky • Optical design analysis • Development of new data reduction techniques Fraser Clarke

19. Progress - slicer prototype • Price quote for slicer prototype • 1 arm spectrograph optics available • Need lab test up with phase screen, and simple coronagraph (or should we move our setup somewhere else) • Procurement for detector and readout system launched. Fraser Clarke

20. Progress - SINFONI coronagraph • Proposal to ESO for instrument upgrade in preparation • MPE would not like to be formally involved, but offers to help. • Request for manpower funding to go in to STFC soon (already?) • Hardware funding? (ESO) Fraser Clarke